Fluid inlet for rotary mixers



March 1940- Y w. c. LUDINGTON 2,192,406

FLUID INLET FOR ROTARY MIXER Filed Oct. 251, 1938 3 Sheets-Sheet 1 INVENTOR March 5, 1940. w. c. LUDINGTON 2,

FLUID INLET FOR ROTARY MIXER Filed Oct. 51, 1938 's Sheets-Sheet 2 I INVENTOR M/I'Mm Cal-rol/ludlhgfan March 5, 1940. w. c. LUDINGTON FLUID INLET FOB ROTARY MIXER 5 Sheets-Sheet 5- Filed Oct. 51, 1938 INVENTOR #4702901 Carm/Mudingfon Patented Mar. 5, 1940 FLUID INLET FOR ROTARY MIXERS William 0. Ludington, Wilkinsburg, Pa., assignor to Blaw-Knox Company, Blawnox, Pa., a corporation of New Jersey Application October 31, 1938, Serial No. 237,812

' 4 Claims. (01. 259-168) This invention relates to a mixer and, in particular, to means for supplying fluid to the interior of a mixer. The invention is specially adapted for the supplying of water to the interior of a coni crete mixer but may be used in other applications.

In the use of traveling concrete mixers, it is desired to mix the batch dry en route and then add water thereto before the final mixing. The water used in mixing the batch is usually carried in a 1o tank on the upper part of the superstructure of the mixer. Because of the limits imposed by road clearances, the elevation of the water tank above the mixer proper cannot be very great. The

water to be supplied to the tank is thus under a relatively low head and difiiculty has been experienced heretofore in obtaining the discharge of water into the mixer with the desired rapidity.

The apparatus which has been used heretofore for distributing the water to the interior of the mixer is of such nature as to be blocked quite readily by the contents of the mixer so that the supply of fluid to the latter is relatively slow and uncertain.

I have invented a novel apparatus for supplying water to the interior of a mixer which is capable of discharging a large volume in a relatively short time. prises a conduit extending radially of the usual rotatable mixer drum, the conduit being rotatable in the same direction as the drum and conveniently secured thereto. The conduit is provided with a discharge head which is disposed substantially tangentially relative to the direction of rotation of the conduit and mixer and facing rearwardly. By this arrangement, the discharge head on rotation through the contents of the mixer is not subject to blocking by the latter and a rapid discharge of water therethrough is obtained. A further feature of the invention is the provision of means for preventing the contents of the mixer from flowing backwardly into the fluid supply conduit. Various forms of the above described embodiment of the invention are illustrated in the accompanying drawings. In the drawings:

Fig. 1 is a partial section, largely diagrammatic, through a mixer having the invention applied thereto, on an axial plane, parts being shown in elevation;

Fig. 2 is a transverse sectional view taken sub stantially along the plane of'line IIII of Fig. 1;

Fig. 3 is a rear elevation of a discharge head; Fig. 4 is a sectional View taken along the plane of line IVIV of Fig. 3; r

Fig. 5 is a view similar to Fig. 1 illustrating a 5 modification; r

A preferred form of the invention com-- Fig. 6 is a sectional view taken along theplane of line VI-VI of Fig. 5;

Fig. '7 is a partial sectional view similar to Fig. 6 showing a further modification, the plane of section being that containing the axes of the water supply conduits;

Fig. 8 is a view similar to Fig. 7 showing a further modification; n

Fig. 9 is a side elevation, partly in section, of a further modified form of fluid supply apparatus; .10 and Fig. 10 is an elevation of the apparatus shown in Fig. 9 such as would be seen by looking on the latter from the right.

Referring now in detail to the drawings, and.- .1l for the present to Figs. 1 through 4, a mixer drum indicated generally at H! is mounted for rotation by means already well-known whereby it may be driven to mix thoroughly the material therein.

'A charging and discharging opening I l at one end go of the drum is normally closed by a closure I 2. A water supply conduit l3 extends into the drum from the end opposite the charging opening, being supported at that end by a central casting l4 and adjacent the other end by a spider IS, the legs of',;25 which terminate on the wall of the drum.

A branch fitting I6 is connected in the conduit l3 and radial conduits H extend therefrom as clearly shown in the drawings. Each radial conduit I1 is provided with av discharge head l8, the =30 construction of which may best be seen in Figs. 3 and 4. As there shown, each head or outlet l8 comprises a substantially bell-shaped body [9 and a neck 20 which is threaded for connection to the conduits H. The bell-shaped body portion of the;; 5

head terminates in a flaring mouth 2|. A shoulder Z2 spaced inwardly from the mouth2l provides a seat for a flexible diaphragm 23 of rubber or other suitable material. The diaphragm 23 is carried on a. screw 24 threaded into a post 25,.

which projects from the wall of the body portion toward the mouth 2 I The diaphragm is disposed on the screw between backing plates 26 and 21. The plate 21 has holes 28 formed peripherally thereof. The diaphragms 23 is of such character.;;45 that a slight excess of pressure on the inner side thereof will suflice to deform it sufiiciently to permit a free flow of water from the mouth of the discharge head. Upon reversal of the pressure, the diaphragm tightly seals the mouth of the head,-. 50 thus constituting a check valve.

The conduit [3 is connected to the water tank usually carried on portable mixing units through any suitable swivel connection. The conduit and the assembly of branches and discharge heads r line 30. On opening of the water control valve between-the tank and the conduit 13, water will be supplied to the conduit and flow thence through the branches 'i'! and the heads 18. of flow will naturally be greatest through the branch extending to the lowermost head. It will be apparent that the contents of the drum do not obstruct the flow of water from the heads since the motion of the latter through the batch opens a clearance space-for the water and may even produce some slight suction'effect to accelerate the flow from the heads. At the same time; the diaphragms 23 prevent any back-flow of the materials' of the batch into the heads l8, should conditions ever tend to cause this result.

1 It will be apparent that the apparatus described is capable of more rapidly discharging a given volume of water into the drum than water supply means previously used. In a comparative test, the apparatus of my invention discharged more than twice as much water in a given time as a water supply means of a prior type. The concrete ismixed to a uniform consistency but no batch materials are found in the heads after use. The diaphragms exhibit no deformation and no special attention to the water supply means is necessary, other than the ordinary flush-out at the end of a days operations. The discharge heads, being generally bell-slipped, traverse the batch without imposing excessive stress upon the v conduit l3, fitting E8, or branches ll.

Figs. 5=and 6 illustrate a modified construction,

- according to which a mixer drum 3! is provided with a fluid supply conduit 32 having branches 33 extending around the end thereof and for a short distance along the length thereof. the branches 33, short conduits 3d extend radially into the drum and at their ends are provided with heads i8. As in the arrangement of Figs. land 2, the heads or outlets l8 are directed rearwardly of the direction of rotation-indicated by the arrow 35 and are disposed substantially tangentially. The operation of the apparatus shown in Figs. 5 and '6 is quite similar to that of the system previously described.

Fig. 7 illustrates a further modification according to which a conduit 36, corresponding to that shown at l3,'is provided with an annular fitting 31, both the conduit and fitting being bored to receive radial branches 38. The latter are provided with heads or outlets 39, similar in general to those shown at l8 except that they are shaped to engage the interior of the wall of the rum ill and are secured thereto as by screws in. A cleanout opening is'normally closed by a plug M. The rearwardly directed mouth of the head 39 is pro- 'vided with a diaphragm check valve assembly indicated generally at 62, substantially identical with that, shown in Fig. l.

Fig. 8 illustrates another modification generally similar to that of Fig. '7. In Fig. 8, branch conduits 43 extend from a central axial conduit and penetrate the drum wall,the outer end of each branch conduit being closed by a plug 44 which maybe removed for clean-out. A head or outlet The volume tioned discharge terminal within the drum and From outwardly therefrom in the same manner asin conduit corresponding tothat shown at 13. 5 if The casting has a hub connected in the conduit 48 and branches or elbows 49' extendinggenerally radially therefrom, the outer endof each branch having a head or outlet 50 formed therein with a mouth normally closed by a diaphragm 10 check valve assembly 5|. It will be understood that the devices shown in Figs. '7 through 10 function in substantially the same manner as that of Figs. 1 through '4 to provide rapid inflow of water from the supply tank to the mixer drum 15 proper. This is an important advantage because it is desired that the entire mixing operation be completed while the truck mixer is on its way to the point of delivery, and sometimes this is only a short trip.

While I have disclosed only a few embodiments; of the 'inventio-n, it' will be understood that] changes in the construction illustrated'and described may be made without departingifrom the spirit of the invention or the scope of the appended claims.

I claim:

1. In amixer, a rotatable drum, a fluid supply system therefor comprising an eccentrically posimounted for rotation therewith, said discharge terminal having an outlet opening in a direction opposite to that in which the drum normallyrotates, and, pipe connections for conducting water from a source of :supplyto said discharge terminal comprising a central supply pipe and a branch pipe leading from the central supplypipe to said terminal and so disposed that any head of liquid available at the central supply ,pipe' for causing discharge will be increased as'the terminal moves I downward during the rotation of the mixer drum.

2. Ina mixer,'a rotatable drum, a fluid supply system therefor comprising an eccentrically positioned discharge terminal within the drum and mounted for rotation therewith,said discharge terminal having an outlet opening in -adirection opposite to that in which the, drum normally rotates, pipe. connections for conducting water from'a source of supply to said dischargeterminal comprising a central supply pipe and a branch pipe leading from the central supply pipe, to said terminal and so disposed thatany head of liquid available for causing discharge will be increased as the terminal moves downwarde to exclude the contents of the drum from being forced into the terminalwhen the direction of rotation of the drum is reversed to discharge mixed material therefrom- 3. Apparatus for introducing water'into a ro-'-;v tatab-le mixing drum comprising a water supply pipe, a conduit communicating with said pipe and rotatable with the drum and having a; discharge terminal thereon which opens into; the drum in adirection tangentially opposite to the direction of 'o rotation of thedrum, thelength'of the conduit in a circumferential direction from the supply pipe to the discharge terminal being substantially less than the diameter of the drum whereby the hydraulic head efiective for causing-discharge 01%.75

2,192,400 t I y 3 normally rotates while the contents of the drum is being mixed, and pipe connections attached to the drum for conducting water from a source of supply to said terminal sovdisposed that the flow of water within said pipe connections attached to said drum is continually downward when said 5 terminal is'in its lowermost position.

. WILL/1AM c. LUDINGTON. 

